Grinding or pulverizing machine



5, 1930- s. A. KNOWLES 1,772,150

GRINDING OR PULVERIZING MACHINE F le g- 1928 4 Sheets-Sheet 1 gwuanfoo 4 Sheets-Sheet 2 Aug. 5, 1930. s. A. KNOWLES GRINDING OR PULVERIZING MACHINE Filed Aug. 14, 1928 gwwmtoz Q AK mN Aug. 5, 1930.

S. A. KNOWLES GRINDING OR FULVERIZING MACHINE- Filed Aug. 14, 1928 4 Sheets-Sheet Aug. 5, 1930. s. A. KNOWLES GRINDING OR PULVERIZING MACHINE Filed Aug, 14, 1928 4 Sheets-$heet 4 v Patented Aug. 5, 1930 SILAS A. KNOWLES, 01 DENVER, COLORADO GRINDING OR PULVERIZING MACHINE Application filed August 14, 1928. Serial No. 299,553.

This invention relates to grinding mills,

and more particularly to that type in which the material is fed to a central hopper or receiving compartment and discharged radially by centrifugal force.

In mills of this type the particles to be ground have heretofore been thrown violently and directly against annular impact plates or abutments and in this manner crushed or ground. There is little or no mutual grind-' ing between the particles and the impact of the material against the annular plates or I abutments rapidly wears such plates so that their replacement at frequent intervals is made necessary.

Also in that type of mill where there is mutual grinding action between the particles they are usually packed close in the casing and forced in well defined streams, the individual particles not only rubbing against each other but against the housing or casing in which they are confined which also causes excessive wear. In these mills therefore the attrition produced is mainly between the particles and the im act plates or abutments or between the particles and the housing. It is therefore one ofthe principal objects of this invention to not only avoid the excessive wear produced by the engagement of the particles being ground with'the casing or impact plates and to thereby avoid excessive maintenance costs, but to construct a grinding mill in which the grinding action is purely between the particles themselves so that there is substantially no contact or an inappreciable contact between the particles and the parts which confine them until such particles have been ground to the required fineness, which then has no material effect in producing wear on the housing.

Another object ofthe invention is to provide a machine having the above characteristics which can be utilized for grinding or pulverizing various materials such for instance as rock, ore, coal and similar material and in which adjustments may be conveniently made to insure a product of any practical degree of fineness.

Further objects of the invention will ap pear as the following specific description is read in connection with the accompan ing drawings which form a tion, and invwhich part of this app iea- 1 is a top plan view; Fig. 2 is a vertical section taken on the line 22 of Fig. 1;

Fig. 3 is a verti the line 3--3 of F cal sectional view taken on ig. 1; e

Fig. 4 is an enlarged detailed sectional view of the upper portion of the rotor and attrition rin and ig. 5 is a vertical sectional-view showing a modified type in which a plurality of grinding units are mounted on a common drive shaft.

able type of base The shaft, it will-of course be understood, may be driven by any suitable power plant. As here shown I have mounted thereon a pulley 5 which may be belted to an electric motor or steam engine as is foundmost desirable and economical, but it will be understood thatthe shaft may be, if desired, connected directly to the armature shaft of an electric or fluid motor.

Secured to the outer end of the shaft 1 v is a plate 6 to which is clamped a plurality' of radiating tubes short of the axis circular pocket 8 7 each of which terminates of the shaft 1 and form a into which the material to be ground is. fed as will be hereinafter explained. The tubes or radial passages 7 are clamped to the plate 6 by means of annular rings 9 and 10, the former having its inner edge flush with the inner edge of the tubes 7 as shown in Fig. 3. The outer ring is substantially L-shaped in. cross section, having one leg lying across the face or sides of the tubes and the opposite or right-angular leg positioned over the ends of the right-angular extension 11 formed on the end of the plate 6 and having apertures or ports 12 therein coinciding with S extension 11.

I is fed through the slot 16 into the receptacle its outer end closed by a damper and its side provided with an opening in the ,form of a circumferential slot 16 which registers with the opening in the lower end of a su ply hopper 17. Thissupply hopper may e mounted in any suitable fashion and carries the supply of the material'to be ground which I 14 and from thence into the pocket 8 where a rotarv motion is imparted and the material discharged by centrifugal force through the tubes 7, the damper 15 being supplied to control and regulate the amount of air admitted in accordance with the requirements of the machine as will be more fully hereinafter explained.

Mounted upon opposite sides of the machine and on opposite sides of the tubes 7 are plates 18 having central apertures 19 to receive respectively the hub 20 of the plate 6 and the receptacle 14. Surrounding the opening 19 which receives the hub20, is a suitable packing ring 21 which engages the hub 20 to prevent theescape of the ground or pulverized material. In the embodiment shown in the drawing the plate 18 which receives the receptacle 14, is bolted or otherwise sea cured to an annular flange on said receptacle 14, and the hopper 17 is plate.

Adjacent the periphery of the plates 18 I secure therebetween by bolts 22 or in any other suitable manner an attrition ring which I have generally indicated by the letter A and which may be made as an integral casting or in two parts 23 and 24 as shown. This attrition ring constitutes the stator of the machine. I preferably construct the ring as illustrated in the drawings in order that the inner ring which receives the material from the tubes may be replaced in case of necessity but as there is no appreciable wear on this ring so faras I have been able to determine from practical tests, the attrition ring might be made of a single integral part if desired. Asshown in Figs. 2 and 3 the inner ring 24 is provided with an annular pocket 25 of somewhat larger diameter than the internal diameter of the tubes or the apertures 12 and 13 and whose cross sectional axis is offset also bolted to said from the axis of the tubes so that the entrance at intervals as shown in Fig. 2 for a purpose vided with an annular rib 29 having an inclined outer peripherial surface 30 which is parallel to a corresponding surface 31 formed on the inner face of the ring 24 at one side of the entrance channel 26 so as to provide an annular discharge opening 32.

On the opposite side of the entrance channel 26 the inner wall of the ring 24 is parallel with the axis of the ring and parallel to the periphery of the ring 10 but spaced away from said ring to provide a supplemental discharge opening 33 whose size never varies. The size of the discharge opening 32, however, may be varied by shifting the attrition ring A in either direction and for this purpose I support the lates 18 and said ring A in such manner t at they maybe moved longitudinally with respect to the shaft 1 and yet constantly maintain the concentric relation between the shaft and the attrition ring. As shown in Fig. 2 the outer ring 23 is provided with laterally extending supporting ears 34 which rest upon the base 4 and are secured thereto by bolts 35 which extend through elongated slots 36 formed in said ears. These ears are preferably strengthened by suitable webs 37 or in any other preferred manner. When the bolts 35 are loosened the plates 18 and the attrition ring A may be shifted toward or away from the bearings 2 so as-to adjust the wall 31 with respect to the wall 30 and to re ulate the size of the discharge opening 32.

ach of the plates 18 is as shown in Fig.

3 provided with an outwardly projecting portion 38 which forms a pocket 39 for receiving the ground or pulverized materlal and from which said ground or pulverized material may be discharged through a sliding door or in any other suitable manner. In fact if found desirable the discharge from the pockets 39 may be continuous to a storage bin or any other suitable receptacle through i a discharge passage 40as shown in Fig. 2.

In the operation of the device thus far described the rotor which consists of the plate 6, tubes 7, and rings 9 and 10 and. which I shall designate generally at Bis rotated at high speed the R. P. M. s depending largely upon the material being acted upon an by the degree of fineness to be desired in grinding the material. When the shaft 1 and the rotor B are rotating at the correct speed for the material being acted upon the said material is fed into the hopper 17 and into the receptacle 14 along with air which is sucked in through the slot 16 by the suction produced in the rapid rotation" of thetubes. This air and material to be ground passes into the inner ends of the tubes 7 and is thrown outwardly by centrifugal force passing through the entrance channel 26 into the annular pocket 25 at a tangent. As will be seen from an inspection of Figs. 3 and 4 the dimension of the discharge opening 32 is considerabl less than the cross sectional area of all 0 the tubes 7 which insures a maximum quantity of air being pocketed within the annular channel 25 so that after the material enters this channel the air therein produces an effective cushion around the Wl-il so that if the material touches this wall it only contacts with the same very lightly.

tion among themselves.

In fact, I have found by experiment that after operating the machine for a considerable length of time sand from the core with which the channel 25 was formed still remained and sand particles were not eliminated' which seems to conclusively prove that the material entering the channel 25 at a tangent does not contact. with the wall but whirls around in said channel in a. path concentric with the cross sectional axis of the channel and producing a vortex,draws mate- /rial toward said cross sectional axis thereby causing the particles to rub against each other and producing a mutual grinding ac- Furthermore, it is to be noted that the material discharged from the tubes-into the channel 25, after the initial start of the machine, will impinge directly against the body of material in the vortical whirl, whereby the material in said whirl is caused to act as an impact abutment for the incoming material.

The-ring A being stationary the natural course of the material being treated would be to follow the course of the peripherial ends of the tubes 7 that is to say to travel in apath within the channel which is concentric with the axis of the rotor, and in order toprevent this I have provided the lugs 28, with square shoulders arranged in the path of the normal movement of the material as it is discharged from the tubes. These lugs also fail to show any wear after a considerable period of operation of the machine and it is assumed that the air within the channel 25 being under compression produces a cushion around the wall of the channel 25 and over the square surface of the lugs 28 so as to prevent'contact of the particles of material thrown into the channel by centrifugal force from-the tubes. The amount of this compression within the channel 25 is of course determined b ---responding coarser one. There will, however, at all times be maintained within the channel 25 a sufiloient cushion of air around the walls and against the square face of the lugs to appreciably reduce the impact contact of the material with said walls or lugs and for this purpose I have provided the damper heretofore mentioned which may be regulated to admit more or less air as desired. When the opening 32 is-made com paratively small to produce a very fine madled, so that the required amount of air is admitted with the material and the material entering the channel 25 .will be prevented from contacting with the walls thereof. This assures a proper vortical action within the channel and an intimate rubbing and mutual grinding action between the particles. Furthermore, one of the walls defining the opening 32,'namely the wall 30, is constantly moving during the operation of the machine, thus insuring a non-clogging discharge passage for the material being ground.

It will of course be well understood that the major portion of the round or pulverized material is discharged from the channel 25 through the opening 32 but some of this material along with quantities of air is v also discharged through the opening 33. All material discharged either from the opening 32 or the opening 33 passes downwardly along side of the rotor and enters one of the pockets 39 Where it'may be continuously-or intermittently discharged "as is found desirable. I have found in practice that con tinuous discharge is calculated to produce a more even and uniform operation of the machine but it will of course be understood that the sliding doors heretofore referred to may be kept closed and a vent provided for air discharge.

While I have shown the preferred form of adjusting the size of the discharge opening 32, namel by adjustin the rotor. housing on the base, wish it to Ive clearly understood that other forms of adjustment; of this dis-.

h I bt d. the relation of the wall 31 to the wall 30 and c arge opemng may be readlly 0 mm For instance, the-rotor housing could be'made stationaryand the ring 24 adjusted upon the rin 23 or the entire housing and ring A. mig t bemade stationary and the shaft 1 shifted longitudinally in the bearings and. held in its adjustedposition by a suitable thrust bearing member. 1

It will'benoted that the tubes 7 are held in proper position both as to annular and and are further held against radial movement by the overhanging flange 11 of the disc or plate 6, which latter part is made relatively eavy as is the ring 10 so as to act as aflywheel.

In the form of the device shown in Fig. 5 I have shown a plurality of attrition rings and rotors arranged in superposed relation on a common drive shaft. This drive shaft as shown is mounted in bearings 41 and 42, the latter being supported in a spider '43 supported upon. the upper portion of the housing 44 which is preferably constructed in two halves so that one of them may be read- 11y removed to gain access to the rotors and attrition rings. As shown in this figure the rotors and attrition rings are graduated in size, the smaller ring being arranged at the top and then gradually increased in size toward the lower ring which is the largest in point of circumference. The cross sectional area however of the attrition channels in each ring is identical but the openmg provided for discharge of the ground or pulverized material in the upper ring is made considerably larger than that in succeeding lower rings so that a relatively coarse material is discharged from the upper ring and this gradually reduced to the required s ze by attrition in the succeeding lower rlngs In producin the adjustment to determlne the size of t e discharge openings, I preferably ke the rotor to the shaft by a spllne or feat er key and seat the same on the shaft by suitable set screws 45 but it will be understood that the rotors maybe fastened on the shaft'and the attrition rings adjusted with respect thereto in the housing.

In this form of the device material enters the open upper end. of the housing and is discharged into the hopper 46 whose inclined sides convey the same to the pocket 8 defined by the ends of the tubes 7. The material is then thrown outwardly through the tubes by centrifu al force into the attrition channels 25 and w hen properly ground to the reduired s1ze to pass-through t e opening 32 is discharged onto the next succeeding hopper indicated at 47. The operation here is repeated and the material discharged from the second lower ring is received by the hopper 48 and delivered to the pocket 8 of the lower rin s.

By graduall increasing the size of tie rotors it will e seen that as the material proceeds downwardly toward the lowest rotor which is operated at the same speed as the uppermost rotor, the centrifugal action is increased and the vortical action within the attrition channel is also increased so as to get a more intimate rubbing and grinding betweenthe particles and thus a finer produ-t not. This final product is discharged upon the lower hopper 49 whose inclined sides convey it to-the central opening 50 where itis discharged into any suitablereceiving vessel.

It will be noted that the upper unit has a relatively large pocket 8 for receivin the material from the hopper 46 the size oFthis pocket being proportioned in accordance with the size of the discharge openings 32 so as to insure a suflicient quantity of air being delivered to and retained in the attrition channel to form a cushion for the material and at the same time produce the re-.

quired vortical action. This same proportioning of the pockets 8 and open ngs 32 1s carried out throughout the succeedlng lower rings the pockets being decreased in size in tubes 7 and that any material to be ground 1 which is initially received in larger particles than could possibly passthrough the tubes must undergo some preliminary grinding or crushing and then be placed in the hoppers for treatment in the attrition channels.

' I have shown the tubes in both forms of the device as being ;of a rectangular outline;

but I wish it understood that these tubes may be oblong in'c'ross section, square, round or any other shape as may be found deslrable In practice. The rectangular type of tube 1s much more readily associated one with the other at the inner ends which form the pockets, butround tubes may be used with filler pieces to close the openings between the tubes and the clamping rings. Such modifications as these ma be resorted to without 1n any way departing from the spirit or scope of the invention and are considered to be well within the purview of the appended claims. 0

While I have described this machlne as operating with air, yious, and with slight modificatlons, that a suitable gas may and such gas supply might be found deslrable, particularly in the preliminary treatment of ores during grinding, and prior to subjecting said ground ore to the various processes of separation.

VVhatI claim is 1. The method of grinding materlals which-consists in producin a rapid radlal movement thereof and then ringing the ma terials into intimate rubbing contact by a vortical action-"in a substantially confined space. v

2. The method of grinding materials which consists in producing a vortical action within a cushion of air .in a substantially confined space to cause intimate rubbing action. 4

3. The method of grinding materials whlch consists in producing a forceful radial movement thereof from one axis andthen' causing it will of'course be obe-used instead of -a1r,

a vortical whirl on another axis within a substantially confined space.

4. The method of grinding materials which consists in producing a forceful radial movement thereof from one axis and then causing a vortical whirl on another axis, at right angles to the first axis and within a substantially confined space.

5. The method of grinding materials which consists in causing predetermined quantities of air or gas and material to be discharged from a startmg axis by centrifugal force and causlng said air or gas to form an impact cushion and a vortical whirl within a substantially confined space, whereby the particles of material are brought into intimate wearing contact among themselves within the whirl.

6. The method of grinding materials which consists in causing predetermined quantities of air or gas and material to be discharged from a starting axis by centrifugal force and causing said air or gas to form an impact cushion and a vortical whirl within a substantially confined space, whereby the par-. ticles of material are brought into intimate wearing contact among themselves within the whirl, the material within said whirl producmg an impact abutment for material dis- I the rotor on an 3X18 at right angles to the charged into said whirl;

7. The method of grinding materials which consists in causing predetermined quantities of air and material to be discharged from a starting axis by centrifugal force and causing said air to form an impact cushion and a vortical Whirl within a substantially confined space, whereby the particles of material are brought into intimate wearing contact among themselves within the whirl, and regulating the quantity of air in accordance with the character of the product desired.

8. In a grinding mill, a stator, a rotor revolubly mounted in the stator and adapted to receive the material to be ground adjacent its axis and discharge the same peripherially, and means forming a substantially confined space in the stator for producing a vortical iwhirl of the material dischargedfrom the roor. 9. In a grinding mill, a stator, a rotor revolubly mounted in the stator and adapted to receive the material to be ground adjacent its axis and discharge the same peripherially, means forming a substantially confined space in the stator or producing a vortical whirl of the material discharged from the rotor, and means for preventing impact contact of the material with the stator.

10. In a grinding mill, a stator, a rotor revolubly mounted in the stator and adapted to receive the material to be ground adjacent its axis and discharge the same peripherially, means forming a substantiallyconfined space in the stator for producing a vortical whirl of the material discharged from the rotor, means for preventing impact contact of the "element.

to receive the material to be ground adjacent its axis and discharge the same peripherially, means forming a substantially confined space in the stator for producing a vortical whirl of the material discharged from the rotor, and pocket-forming members in the stator to prevent circumferential movement of the material in the stator.

13. In a grinding mill, a stator, a rotor revolubly mounted in the stator and adapted to receive the material to be groundadjacent its axis and. discharge the same peripherially, means forming a substantially confined space in the stator for producing a vortical whirl of the material discharged from rotor axis, and means to prevent movement of the material around the rotor axis.

14. In a grinding mill, a stator element, a rotor element arranged to receive material to beuground and discharge the same peripherially into a substantially confined space within the stator element, said elements being relatively adjustable to regulate the discharge'opening for the ground material.

15. In a grinding mill, a stator element, a rotor element arranged to receive material to be ground and discharge the same peripherially into the stator element, the arrangement of said elements providing a discharge openingfor the ground material between the elements, one of said elementsbeing adjustable in a path parallel to the axis of the other 16. In a grinding mill, a stator element, a second element arranged to-rotate within the first element, to receive the material to be ground and discharge the same into the stator element, the arrangement of said ele ments providing a discharge opening for the ground material between the elements, and means for altering the relative positions of said elements to govern the size of said open- I'Z. In a grinding mill, afstator element, a second element arranged to rotate within the first element, to receive thematerialft be ground and discharge the sameinto the stator element, the arrangementof saidelements providing a non-clogging d scharge opening forthe ground mate 'i aMJQfi liGGfi Q elements, means for altering the relative p0 sitions of said elements to govern the size of said opening, and means for admitting air or gas to said rotating element so that the admission may be made proportional to the 5 discharge from said opening.

18. In a grinding mill, a stator element, a secondelement arranged to rotate within the first element, to receive the material to be ground and discharge the same into the stator element, the arrangement of said elements providing a discharge opening for the ground material between the elements, means for altering the relative positions of said elements to govern the size of said'opening,

5 and a damper for controlling admission of air or gas to said rotating element'so that the admission can be made proportional to discharge from said opening.

'19. In a grinding mill, a stator element, a

second element arranged to rotate within the first element, to receive the material to be ground and discharge the same into the stator element, the arrangement of said elements providing a restricted non-clogging discharge opening for the ground material between the elements, and means for adjust- 'ing' the size of said opening.

20. In a grinding mill, astator element, a rotor element arranged to receive material to be ground and discharge the same peripherially into the stator element, the arrangement of said elements providing a discharge opening for the ground material between the elements, and means for adjusting the stator axially of the rotor element to govern the size of said opening.

21. 'In a grinding mill, a rotor arranged to receive material to be ground and discharge the same peripherially, a stator having an o annular channel forming a substantially contobegroundand discharge the same periphe-' rially at high velocity into the stator element where it receives a right angle whirl,

the inner surface of said stator element being circular and the center line thereof being at one side of the discharge openings-from the rotor element, whereby a circular motion is imparted to the material entering the stator element from the rotor element, thus permitting the incoming large sized material to grind or pulverize the smaller sized material within 'the stator element.

In testimony whereof I afiix my signature.

SILAS A. KNOWLES.

so V

to alter the path of entrance of material into I said channel.

2 3. The method of grindin material which consists in producing a igh radial velocity of the material to be ground and then changing the direction of said material to a right angle whirl, bringing the material within said whirl in contact with the incomo :ing material being discharged radially, thus causing the larger sized material to pulverize the smaller sized material.

i24 -J=.I n a'g'rinding mill," a'stator element, a rotor element revolubly mounted in the stator .5 element and adapted to receive theanaterial 

